Biomarkers of asbestos exposure: All forms of asbestos including the amphiboles (crocidolite, amosite, tremolite, actinolite, and anthophyllite) as well as the serpentine form chrysotile, cause mesothelioma and cancer of the lung. Therefore, it would be highly desirable to have available sensitive and specific biomarkers of asbestos exposure in order to assess potential inter-individual risks of developing mesothelioma or lung cancer. In on-going studies, we are developing serum metabolomic markers of exposure to asbestos. This has involved the implementation of nanospray ultraperformance liquid chromatography (UPLC) in combination with high resolution tandem mass spectrometry (MS/MS). Individual samples are extracted with a suitable solvent (Folch extraction) then aqueous and organic phases are subjected to analysis by high resolution nanospray UPLC-MS. Individual chromatograms are aligned using a combination of open-source and proprietary software. Chromatograms from control samples are then interrogated against experimental samples for differences in intensity of each MS signal. Identification of metabolites is conducted by using different modes of MS/MS analysis. These studies have resulted in the generation of a rich data-set of biomarkers, in which a number of metabolites are dysregulated in asbestos exposure when compared with control non-exposed individuals. Therefore, we are poised to develop a robust biomarker panels for both asbestos exposure and mesothelioma. We will test the hypotheses that: 1) Asbestos exposure will increase oxidative stress as revealed by current serum oxidative stress biomarkers. (2) Metabolomics analysis of serum using ultra-high resolution LC-MS will reveal novel biomarkers of asbestos exposure and mesothelioma that can be characterized using modern bioanalytical techniques. (3) Profiling of human serum proteins will identify signatures of asbestos exposure and mesothelioma. These hypotheses will be tested under the following three Specific Aims. Aim 1: To quantify biomarkers of oxidative stress and identify and quantify differentially secreted metabolites in the serum of human subjects exposed to asbestos, serum from subjects with mesothelioma, and control serum from normal unexposed control subjects. Aim 2: To quantify biomarkers of oxidative stress and identify and quantify differentially secreted metabolites in asbestos-exposed immortalized mouse cells and serum provided by Project 4 from mice genetically engineered to develop mesothelioma compared with isogenic non-exposed mice. Aim 3: To analyze serum HMGB1 and profile serum proteins (SOMAmer assay) in asbestos-exposed and unexposed individuals to identify asbestos exposure biomarkers and to analyze serum fibulin-3 as a mesothelioma biomarker to complement serum metabolomic biomarkers obtained in Aim 1. Successful completion of these studies of asbestos exposure would have a significant translational impact for risk assessment and management within the local community. It would have an immediate impact on risk communication and risk management that would be rapidly translated to other members of the SRP through the regular research meetings. It would also impact on regulators of risk assessment and risk management. Another translational impact would be the use of biomarkers for monitoring disease prevention and treatment as well as the identification of individuals at risk for follow-up studies. It will be possible to identify particular individuals who have been exposed to asbestos and have a high risk profile for careful clinical monitoring or asbestos-exposed individuals lacking a high risk profile.